Medication adherence issues in patients treated for COPD.

Although medical treatment of COPD has advanced, nonadherence to medication regimens poses a significant barrier to optimal management. Underuse, overuse, and improper use continue to be the most common causes of poor adherence to therapy. An average of 40%-60% of patients with COPD adheres to the prescribed regimen and only 1 out of 10 patients with a metered dose inhaler performs all essential steps correctly.